Treating hectograph bands



Patented Dec. 14, 1937 PATENT OFFICE TREATING HECTOGRAPH BANDS William B. Whitmore, Oak Park, 111., assignor to Ditto, Incorporated, Chicago, 111., a corporation of West Virginia No Drawing. Application December 9, 1935,

Serial No. 53,616

12 Claims.

The present invention relates to improvements in hectograph pads of the type usually employed in hectograph machines and in their treatment prior to use.

The hectograph pads employed in hectograph or duplicating machines are usually in the form of relatively thin layers of gelatin mass mounted upon long strips of paper or fabric to form a long continuous band, which is rolled upon a spindle or other supporting means for storage and in connection with its use in the duplicating machine. The gelatinous mass employed in such bands, although usually tanned or hardened, has some adhesive characteristics when freshly made and in the roll, there is a tendency for the gelatinous mass to adhere to the back surface of the paper or fabric. Heretofore, in the preparation of the band for storage or shipment in roll form, it has been customary to coat the surface of the gelatinous mass with a powder such as starch or talc to prevent the gelatinous mass from sticking to the back surface of the paper or fabric.

When powders are employed to prevent adhesion in this manner, the powder must be removed from the roll by washing before the roll can be used. This is an operation requiring some time, involving the complete unrolling and rerolllng of the band, and it is sometimes found unpleasant or ocassionally omitted altogether by the user.

In accordance with the present invention, it has been found possible to provide the gelatinous mass of such a hectograph band with a coating which adequately prevents adhesion between the gelatinous mass and the back surface of the backing, the removal of which, if desired, is much more easily accomplished than when powder is used; and which permits of copies being made on a first use of the roll even when the user of a roll falls to remove the coating initially.

The coating, in accordance with the present invention may be applied after the formation of the hectograph band either before or during its enrolling upon a suitable support or spindle.

In accordance with the present invention, it has been found that the surface of the copy mass may be protected and its adhesion to the backing of such bands may be prevented by the formation on the surface of the gelatinous mass of a thin film of a water-soluble high boiling-point polyhydrlc alcohol or ether thereof, such as glycerol, ethylene glycol, propylene glycol or di-ethylene glycol, the lower alkyl ethers of such glycols such as the mono and dimethyl or ethyl ethers and the monobutyl ethers of ethylene glycol and diethylene glycol, and the like. These substances are (Cl. lib-31.6)

preferably employed in dilute aqueous solutions in which the proportion of the coating material may suitably be from 1 to 5%, although somewhat stronger solutions, say up to 10%, may be employed, if desired. The normally liquid coating agents of the character hereinbefore set forth may, if desired, be applied in full strength to form a thin film but in general it is preferred to use them in such dilute solution. When such aqueous solutions are employed, the water appears to be largely or entirely absorbed in the copy mass, leaving on its surface a thin film of the polyhydric alcohol or ether, the thickness of which may be controlled by varying the concentration of the solution applied. By carrying out the invention as hereinbefore described, adhesion of the gelatinous mass to the back of the backing is prevented and at the same time the advantage is secured that bright copies can be made from the band Without a preliminary washing to remove the coating material.

For example, I may employ an aqueous solution of glycerol or glycol containing from 1 to 10% of the polyhydric alcohol, applying it to the band prior to or during the rolling of the latter. A similar solution of other polyhydric alcohols or of Water-soluble alkyl ethers of the polyhydric alcohols as hereinbefore set forth may be employed in the same manner. These coating agents which have been found effective in accordance with the present invention form solutions with surface tension characteristics which cause them to readily spread over and form a thin film on the surface of the gelatinous mass.

In the application of the coating solution to the band, during the formation of the roll, it is preferred that the band be rolled on the spindle under tension while the coating liquid is being applied, the formation of pools or lakes of liquid or air between the convolutions of the roll being thereby avoided. For example, good results have been secured with a tension of two or three pounds per lineal inch of width. The provision of suitable tension upon the band during the rolling of the same also causes an effective and even spreading of the coating solution and prevents the retention between the convolutions of the roll of more than a very thin film, and also forces air from between the convolutions.

The present invention may also be employed in connection with relatively short or individual hectograph pads formed with the copy mass on a backing to protect the surfaces of the pads and permit their being stacked upon one another.

Although the present invention has been described in connection with certain specific embodiments thereof, it is to be understood that the details thereof are not to be regarded as limitations upon the scope of the invention except in so far as included in the accompanying claims.

I claim:

1. A hectograph pad capable of being stacked or wound without sticking to an adjacent pad or adjacent convolutions of the same pad comprising a coating of gelatinous duplicating ma-- terial and an integral non-adhesive film of a;

water-soluble compound of the class consisting of the polyhydric alcohols and .ethers thereof on the duplicating surface of said pad. 7

2. A hectograph pad capable of being stacked or Wound without sticking to an adjacent pad or adjacent convolutions of the same pad com- 7 prising a coating of duplicating material and an integral non-adhesive film of a water-soluble polyhydric alcohol on the duplicating surface.

3. A hectograph band comprising a coating of gelatinous duplicating material and a film of a watersoluble alkyl ether of a polyhydric alcohol on the duplicating surface.

4. A hectograph band capable of being stacked or wound without sticking to an adjacent band or adjacent convolutions of the same band comprising a gelatinous coating, a fibrous backing therefor, and an integral non-adhesive continuous coating of a water-soluble polyhydric compound of the class consisting of the polyhydric alcohols and ethers thereof on the surface of said gelatin coating. 7 v

5. A hectograph band capable of being stacked or wound without sticking to an adjacent band or adjacent convolutions of the same band comprising a gelatin coating, 2. fibrous backing there-' for, and ,an' integral non-adhesive continuous coating of glycerol on the surface of said gelatin coating.

6. A hectograph band comprising a gelatin coating, a continuous fibrous backing therefor, and a coating of glycol on the surface of said gelatin coating.

'7. A hectograph band comprising a gelatin coatinga continuous fibrous backing therefor, and a coating of a water-soluble alkyl ether of ethylene glycol on the surface of said gelatin coating. a

'8. The method of treating a hectograph pad which comprises applying to the gelatinous surface thereof a water-soluble alkyl ether of a polyhydric alcohol.

9. A method of treating hectograph bands which comprisesapplying to the gelatinous surface thereof an aqueous solution of a water-soluble compound of the class consisting of the poly hydric alcohols and ethers thereof, thereby forming; a film of such water-soluble compound thereonl c 10. A method of treating hectograph bands which comprises applying to the gelatinous surface thereof an aqueous solution of glycerol thereby forming-a film of glycerol thereon.

11. A method of treating hectograph bands which comprises applying to the gelatinous surface thereof an aqueous solution of glycol thereby forming a film of glycol thereon. V

12. A hectograph roll comprising a hectograph band wound into roll form, said band comprising a backing, a coating of gelatinous duplicating material thereon and an integral non-adhesive film of glycerol upon the duplicating surface, said non-adhesive filmvserving to prevent adhesion between'the adjacent convolutions-of the hectograph roll.

WILLIAM B. WHITMORE. 

